AB0183 DOWNREGULATION OF TUMOUR NECROSIS FACTOR α GENE EXPRESSION IN CULTURED PERIPHERAL BLOOD MONONUCLEAR CELLS IN THE PRESENCE OF TOFACITINIB PRIOR TO THERAPY AS A PROGNOSTIC BIOMARKER OF CLINICAL REMISSION IN PATIENTS WITH RHEUMATOID ARTHRITIS TREATED WITH TOFACITINIB
Authors: E. Tchetina, G. Markova, A. Satybaldyev
Journal: Annals of the Rheumatic Diseases (2022)

Background Rheumatoid arthritis (RA) is a chronic inflammatory disease characterized by synovial hyperplasia, mononuclear cell infiltration, bone erosion and joint destruction. Recently we have shown that changes in energy generation-related gene expressions in the peripheral blood of tofacitinib (TOFA)-naïve patients with RA are associated with clinical response to treatment [1]. Therefore, considering metabolic status of patients with RA, may be useful for identification of prognostic biomarkers for personal responsiveness to TOFA therapy in TOFA-naïve RA patients by baseline gene expression analysis in peripheral blood mononuclear cells (PBMCs) cultured with TOFA prior to therapy. Objectives To examine the association of changes in expression of the genes responsible for cell growth and proliferation [mammalian target of rapamycin, mTOR], bone and articular cartilage resorption [matrix metalloproteinase (MMP)-9, cathepsin K], and inflammation [tumour necrosis factor (TNF)α] in the PBMCs obtained at baseline from patients with RA and cultured with TOFA with therapy outcome. Methods 12 patients with RA (median age 55 years), median disease duration 28.5 months (without previous history of therapy with TOFA) were examined. 6 of these patients with RA gained remission after 3 months of TOFA therapy while 6 patients, maintained high and moderate disease activity. Control group consisted of 26 healthy subjects. PBMCs were isolated prior to therapy using Ficoll density gradient and cultured with 10 nM tofacitinib citrate (TOFA) during 48h. Cell viability was monitored with 0.2% Trypan blue staining. Total RNA isolated from these cells was used for mTOR, MMP-9, cathepsin K, and TNFα gene expression studies performed with quantitative real-time RT-PCR. Results TOFA was capable of modifying gene expression in cultured PBMCs from the examined patients with RA compared with untreated cells. Baseline expression of all the examined genes was significantly upregulated in cultured with TOFA PBMCs from patients who maintained high and moderate disease activity after TOFA therapy compared with untreated counterparts. In contrast, TNFα gene expression was significantly downregulated in cultured with TOFA PBMCs of patients who gained remission compared with untreated cells. No significant changes in the expression of other examined genes was observed in cultured with TOFA PBMCs from the examined patients with RA who gained remission after TOFA therapy compared with untreated counterparts. Conclusion Downregulation of TNFα gene expression in cultured with TOFA PBMCs compared with untreated counterparts in TOFA-naïve patients with RA prior to therapy might serve a prognostic biomarker of personal positive response to TOFA therapy while upregulation in the expression of the same gene suggests non-response to TOFA therapy. References [1]Tchetina EV, Satybaldyev AM, Markova GA, Samarkina EYu, Lila AM. Putative association between low baseline gene expression in the peripheral blood and clinical remission in rheumatoid arthritis patients treated with tofacitinib. Life (MDPI Basel) 2021, 11(12), 1385; doi:10.3390/life11121385 Acknowledgements This study was funded by Russian Ministry of Education and Science (Project no. 2022-009-1021062512064-0). Disclosure of Interests None declared